The technology is a development of the belt-splicing technology described in the Vortex Air-cooled Press Operating Manual, published by Shaw-Almex Industries Limited, which is incorporated herein.
In the new technology, the splicer includes a top platen assembly and a bottom platen assembly, which are positioned respectively over and under the to-be-spliced belt-ends. The two platens include respective pressure-surfaces, being surfaces that press directly against the splice-area, i.e against the ends of the belt that are to spliced. Both platens have their own heaters, which operate to heat the respective pressure-surfaces, and thus to heat the belt.
The pressure-surface of one of the platen-assemblies is capable of moving towards and away from the belt, with respect to its housing. That platen includes a pressure-bag, which, when inflated, moves the platen, and thereby applies compressive pressure to the splice. The pressure-surface in the other platen-assembly is not movable.
In some types of splicing, the applied heat and pressure serves to vulcanize rubber in the belt and in the splice, but in the kinds of belts that are served by the current technology, generally the belt is of, or includes, a thermoplastic material, and the heat serves to put the material into the plastic zone, such that, upon cooling, the two ends are bonded very securely. The temperatures and pressures required for vulcanization of rubber belt-ends are generally significantly higher than those for thermoplastic belts. The distinction is made between heavy-duty presses, which are robust enough to perform vulcanizations, and light-duty presses which. although less costly, are able to provide the lower temperatures and pressures as required for thermoplastic belts. The press as described herein is a light-duty press.
The technology is concerned with air-cooled presses, and particularly with how rapidly the pressure-surfaces of the splicer can be heated, and can be cooled after the period of heating. For rapid heating, the basic aim is to minimize the mass of the portion of the press that has to be heated, and to use efficient heaters. For rapid cooling, the aim is to provide a high flowrate of cooling air, and to provide sufficient sq.cm of hot metal exposed to the cooling air.